Hydraulic machine.



A. w. HARRIS.

HYDRAULIC MACHINE. APPLIOATIOK FILED 00125, 1911.

III/IIIII/ Ill/ill COLUMBIA PLANOGRAPH CID-,WASHINOTON, n. c.

ALBERT W. HARRIS, 0F GRAND MERE, QUEBEC, CANADA.

HYDRAULIC MACHINE.

Specification of Letters Patent. Application filed October 25, 1911.

Patented Nov. 5, 1912. Serial No. 656,749.

To all whom it may concern.-

Be it known thatI, ALBERT W. HARRIS, a citizen of the United States,temporarilyresiding at Grand Mere, Province of Quebec, Canada, haveinvented certain new and useful Improvements in Hydraulic Machines,fully described and represented in the following specification and theaccompanying drawings, forming a part of the same.

This invention relates to certain improve ments in hydraulic machinery,and has been designed especially for use in hydraulically operated woodgrinding machinery, though if desired it may be used in other relations.It is one object of the present invention to provide a device, theoperation of which is controlled by the fluid escaping from a. hydrauliccylinder of such machines which will indicate whether the cylinder isnormally operating, this indication being given, for example, by thesounding of an audible alarm. The invention, however, is not limited toan indicating device of this character, but includes any other suitablefor the purpose.

It is a further object of the invention, when the invention is used withhydraulically operated .wood grinding machinery, to provide a device forthe operation of which is controlled by the fluid escaping from ahydraulic cylinder of the machine, which will cause an indication to begiven if the operator shall take more than a predetermined time infilling the grinding pocket of the cylinder of such machine with thewood blocks to be ground, or in arranging the wood blocks in the pocket.

A further object of'the invention is to provide a device foraccomplishing these results which may be readily attached to thehydraulic cylinder with which it is intended to be used.

A full description of the device and its operation will now be given asused with a hydraulically operating wood grinding machine, one type ofsuch machine which has been chosen to illustratetheinvention, and thedevice operativelyconnected therewith,

ing shown in the drawings, in which Figure l is a diagrammatic frontelevation partly in section and partly broken away of a wood grindingmachine in which a plurality of hydraulic cylinders is employed to forcethe wood blocks into grinding' relation with a grinding agency, andshowing two of the indicating devices connected to two of the cylinders;Fig. 2 is a section taken on line 2-2 of Fig. 1; Fig. 3 is a sectiontaken on line73-3 of Fig. 2; showing the controlling valve of one of thehydraulic cylinders and one form of the device operatively connectedtherewith; Fig. 4 is an enlarged detail view of the indicatingmechanism; and Fig. 5 is a diagrammatic plan view of a means for theoutlet of the indicating device and a train of gearing for operating thesame.

Referring now to these drawings, the wood grinder shown is a usual typeof hygrinding stone is indicated at tary stone carried by a shaft anysuitable source of the shaft 11 being mounted in adjustable bearingsindicated generally at 12, suitably supported by framing 13' on"supports 14. With this type of machine,'a plurality of pockets 15 areemployed suitably mounted in the frame of the machine in which theblocks of Wood to be ground are arranged. The blocks of wood are forcedinto grinding engagement with the grinding cylinder 10 by plungers orfollowers 16, one of these plungers being provided for each pocket. Theplungers 16 are carried on piston rods 17 of thehydraulic cylinders 18which are suitably supported above the pockets 15. The piston rods 17are operated by pistons 19 working in the cylinders 18, ports 20, 21(dotted lines, Fig. 2) being provided for the admission of fluid aboveand below the pistons 19. The admission of fluids to the cylinders iscontrolled by any suitable valve, such as the piston valve shown inFigs. 2 and 3, and indicated generallyby the numeral 22, a valve beingprovided for each cylinder, these valves being manually operated byhandle 23, the valves, when in one position, acting to admit fluid abovethe pistons 19, and when reversed admitting fluid behind the pistons toreverse the movement thereof. Fluid is supplied to the valves by supplypipe24 connected to a suitable source of fluid under pressure (notshown) and 10, being aro- 11 driven from power (not shown),

gradually closing draulically operated machine. In Fig. 1 the from thevalves to the cylinder by ports 25 (Fig. 3). There are two of theseports 25 for each valve, which act alternately as inlet and outletports, depending on the position of the valve piston. The fluid escapesfrom one of these ports 25 and passage 26 to outlet 27. This valveconstruction shown is a usual type employed with hydraulic cylinders anda more detailed description of the same is unnecessary for anunderstanding of the present invention.

In the operation of the type of hydraulic wood grinder above brieflydescribed, the operator, assuming the piston 19 is at the bottom of thecylinder, moves the valve and admits fluid under pressure below thepiston, raising the piston to the upper limit of its stroke. This upwardmovement of the piston carries with it the plunger or follower 16,leaving the pocket 15 clear, which the operator then fills with theblocks of wood which are to be ground and reverses the valve. Thereversal of the valve admits fluid under pressure above the piston 19,and the piston is slowly forced downwardly, acting through the followerto force the blocks of wood against the grinding cylinder. As the pistonis forced down, the fluid below it is gradually forced out through theoutlet of the valve, the fluid escaping with a rapidity proportional tothe downward movement of the piston. The flow of fluid from the valvewhen the piston is properly operated is regular. If, however, the woodblocks become wedged against the sides of the pocket so that the pistonno longer is properly operated by the fluid pressure, or if for anyother reason the cylinder fails to normally operate, the flow of liquidfrom the cylinder through the controlling valve will diminish or ceasealtogether. 'By the present invention, the flow of fluid from thecylinder is utilized to indicate the operation of the cylinder, and asuitable device has been provided for this purpose, which will now bedescribed.

The specific construction of the device may be widely varied, but itwill be of such a character that a diminution or cessation of flow offluid from the controlling valve will cause an indicating means to beoperated. The indicating means shown and now to be described is onewhich gives an audible alarm, and is electrically operated, but theinvention, broadly considered, is not limited to indicating means of theaudible alarm type nor to indicating means which is electricallyoperated, though for some purposes and in some situations indicatingmeans of this type and so operated is preferred;

The construction which has been chosen to illustrate the invention isshown in detail in Fig. 3. In this figure the device is shown asincluding a casing 30 which is in communication with the outlet 27 ofthe conto, the

trolling valve, so that the fluid therefrom passes through the casing.The casing 30 may be located in any convenient position about themachine, and is connected with the outlet in any suitable manner. Asillustrated, the casing is supported by the outlet pipe 27 beingconnected thereto by an elbow 28. The fluid escaping from thecontrolling valve is delivered to this casing and when the cylinder isnormally operating there is maintained in the casing a column of fluidadapted to exert a predetermined pressure, this pressure beingmaintained by drawing off the normal amount of fluid from the easing atthe same rate at which it is received therein, the column of fluid beingmaintained in the device illustrated at the level indicated at B, (Fig.3), which may be termed the working level. Suitable means for drawingoil" the fluid is provided, as a draw-01f pipe 31, this draw-off beingnormally open, and proportioned to draw oil the fluid at the rate it isreceived when the normal amount is flowing from the cylinder. If therebe a diminution or cessation of the flow from the cylinder to thecasing, the draw-ofl 31 being open, the level of the column of liquidwill be lowered, and the pressure of the column will be reduced and theindicating device operated as hereinafter described. For reasonshereinafter referred casing is divided into two compartments by apartition 32, the column of fluid which controls the operation of thealarm device being maintained in the right hand compartment shown inFig. 3. The specific construction by which the reduction below normal ofthe fluid pressure in the casing causes the indicating device to beoperated may be varied. One eflicient construction, however, for thispurpose includes a diaphragm 33, which is secured in the bottom of theright hand compartment of the casing by a ring 46. The diaphragm 33 hassocured to it a plate 4t? which is fast to a rod 34: passing through abracket 36 integral with the ring 46. This sliding rod is provided belowthe diaphragm 33 with a. collar 35 between which and the lower part ofthe bracket 36 is a spring 37. The diaphragm is held depressed by thepressure of the fluid in the casing, against this spring, the tension ofwhich is so proportioned relatively to such pressure that if the levelof the fluid in the casing falls below the working level B, the springwill cause the diaphragm to rise. When the diaphragm rises, it carrieswith it the collar 35 which in rising engages with suitable contacts 88,making an electrical circuit indicated diagrammatically by the wires a,b, and through such circuit operates the indicator which in the caseshown is an alarm bell 10. The ring of this alarm aflords to the foremanor other person in. personal charge of the mechanism and its operator anindication that cylinder is either not working at all, or 1s not workingnormally. It is further desirable in this type of machinery that theoperator shall not take longer cylinder, and the present inventionprovides means whereby the foreman or other person in personal chargemay be notified if he takes longer than such predetermined time to fillor rearrange the pocket, the device being of such construction as toafford this result. As shown, this result is provided for by increasingthe height of the partition 32 in the casing, so that the height of thecolumn of fluid in the chamber when required may be raised level B tothe higher level indicated at A in Fig. 3. The partition is providedjust above the working level B with a draw-off 41, this draw-off and thedraw-off 31 ootiperating to draw the column of fluid from level A tolevel B in, say, the operator two minutes within which to fill thepocket of the time be taken, the draw-oft 31 being open,

will draw the level of the column below the ment of the casing serves asan outlet for waste fluid, when there is such fluid, as when thecylinder is suddenly reversed to enable the pocket to be refilled orrearranged, this excess of water escaping through an outlet pipe 42.

In woodgrinding machines of the type hereinbefore referred to, as thegrinding operation proceeds the grinding surface of the grinding stonebecomes dull. This dulling of the surface causes a slowing up in theoperation of the machine, and the quantity of Water escaping from thehydraulic cylinders gradually decreases until the surface becomes sodull that it ceases to grind properly and has to be resharpened. Thisdecrease in the water supplied to the indicating device thus takes placewhen the machine is normally operating. It is desirable when the deviceis used with woodgrinding machines to compensate for this gradualdecrease and means are provided for so doing. In the constructionillustrated there is provided a valve as 45 in the outlet or draw-off 31by which the amount of fluid drawn ofi may be regulated. This valve isoperated so that as the amount of fluid entering the casing of theindicating device decreases, owing to'the dulling of the grindingsurface, the valve is gradually shut off to decrease the fluid drawn offfrom the casing proportionately. The valve may be so operated in variousways. In the construction illustrated there is provided a cam plate 50suitably mounted on the machine provided with a cam slot 51 in whichworks a pin 52 on the the particular than a predetermined time to fillor rearrange the wood pockets of the from the normal working twominutes, thus allowing cylinder. If a longer a large excess of end ofthe valve spindle 53 of valve 45. By rotating the cam plate the valve isclosed, the cam slot causing this closing to be gradual. The plate isrotated in any suitable manner, as by train of worm gears 54, 55, 56,57, 58, 59, indicated diagrammatically, the train of gearsbeing actuatedthrough a belt 59 from the shaft 11 of the machine. Assuming thegrinding stone to wear down so as to require resharpening in six hours,the train of gearing is proportioned to throw the valve spindle.through, say, one-half of its play in that time, this throw beinggradual, the rate of flow of liquid from the cylinder being decreased,say, one-half, in such time, and when the stone has been resharpened theoperator moves the cam plate back to its original position.

The operation of the device is obvious in view of the foregoingdescription, but may be briefly reoapitulated as follows: Assuming agrinder pocket of any one cylinder to be empty, the plunger or follower16 and the piston 1.9 of the hydraulic cylinder are at their lowestpositions. The operator then operates the valve 22, admitting fluidunder pressure below the piston 19. The piston 19 rises very rapidly,and the liquid above it is discharged through the valve 22 into theeasing 30. The right hand or working column of the casing is filled withfluid to the level A, the excess fluid escaping through escape pipe 42.The operator now proceeds to fill the pocket and thedraw-offs 31, 41operating, draw the column of fluid in the casing from the level A tothe level B in a predetermined time, at which time the operator isassumed to have the pocket filled. He then reverses the valve 22, admitsliquid above the piston 19, which immediately begins its downwardmovement, slowly forcing out the liquid below it through the valve andinto the casing. The liquid at this time in the casing is at the workinglevel, or level B, draw-off 31 being open and being proportioned to drawoff the liquid as fast as it is received, maintains the level of theliquid in the casing at level B as long as the cylinder is properlyoperating. Now, if the cylinder ceases to operate, or operates slowerthan it should through the blocks of wood becoming disarranged, draw-off31 draws down the liquid in the casing below the working level B, thuspermitting the diaphragm to be forced upward by the spring 37 and thealarm to be sounded.

It is understood that while has been shown and described hydraulicallyoperating wood grinding machinery, it is not limited to such use, butmay be applied equally well where the necessity may arise with otherhydraulically operating cylinders. It is further understood that theconstruction shown and described for carrying out the invention is aprefer eating device to der is normally operating,

able one, but that other constructions might be devised which would bewithin the scope of the invention and the claims hereunto appended.

l Vhat I claim is 1- 1. The combination with a hydraulic cylinder and acontrolling valve therefor, of a device for indicating the operation ofthe cylinder, and means controlled by the fluid flowing from the valvefor causing the indioperate.

2. The combination with a hydraulic cylinder and a controlling valvetherefor, of a device for indicating the operation of the cylinder, andresilient operating means controlled by the fluid flowing from the valvefor causing the indicating device to operate.

3. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, means for maintaining a normal predetermined fluid pressurein the chamber, a device for indicating the operation of the cylinderand means controlled by the pressure of the fluid whereby a lessening ofthe pressure in the chamber causes the indicating device to operate.

4. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, means for maintaining a normal predetermined fluid pressurein the chamber, a device for indicating the operation of the cylinder,an electric circuit for said indicating device, and means controlled bythe pressure of the fluid whereby a lessening of the pressure in thechamber closes the circuit and causes the operation of the indicatingdevice.

5. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, a normally open outlet proportioned to draw off the fluidfrom the chamber as it enters therein when the cylinwhereby fluid may bemaintained in the chamber at a predetermined working level, a device forindicating the operation of the cylinder, and means whereby drawing offthe water below such working level will cause the indicating device tooperate.

6. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, a device indicating the operation of the cylinder, a normallyopen outlet proportioned to draw-oft the fluid from the cylinder as itenters therein when the cylinder is normally operating, whereby fluidmay be maintained at a predetermined working level in the chamber, adiaphragm held in normal position by the pressure of the fluid when atsuch predetermined level,

a spring adapted to move the diaphragm from such position when the fluidfalls below such level, and connections operated by such movement of thediaphragm for causing the indicating device to operate.

7 The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the ehamber is delivered,an indicating device operalive when the water in the chamber falls belowa predetermined working level, means for holding a column of water inthe chamber at a level above such working level, and means for drawingdown the water from the higher level to the working level in apredetermined time, and below the working level in longer time than apredetermined time, whereby the indicating device is caused tooperate.

8. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, an indicating device operative when the water in the chamberfalls below a predetermined working level, means for holding a column ofwater in the chamber at a level above the working level, two draw-offscooperating to draw down the water from the higher level to the workinglevel in a predetermined time, one of the draw-offs operating to drawdown the water below the working level in longer than a predeterminedtime to cause the indicating device to operate.

9. The combination with a hydraulic cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, an outlet. proportioned to draw off the fluid from thechamber as it enters therein when the cylinder is normally operating, avalve in the outlet, means for gradually closing said valve tocompensate for a normal gradual decrease in the fluid delivered to thechamber, whereby lluid may be maintained in the chamber at apredetermined working level, a device for indicating the opera-ion ofthe cylinder, and means whereby drawing off the liquid below suchworking level will cause the device to operate.

10. The combination with a hyr'lranlie cylinder and a controlling valvetherefor, of a chamber to which the fluid from the cylinder isdelivered, an outlet proportioned to draw oif the fluid from the chamberas it enters therein when the cylinder is normally operating, a valve inthe outlet, a movable cam plate having a slot in which works a pinoperatively connected to the valve, a train of worm gears and means foroperating them togradually move the cam plate and gradually close thevalve tocompensate for a normal gradual decrease in the fluid. deliveredto the chamber, whereby fluid may be maintained in the chamber at apremy hand, in the presence of two subscribing determined working level,a device for indiwitnesses. eating the operation of the cylinder, and

means whereby drawing oif the liquid below ALBERT HARRIS 5 such workinglevel will cause the device to Witnesses:

operate. P. M. TILDEN, In testimony whereof I have hereunto set J. A.GRAVES.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

